Nonvolatile multistate memories in BiFeO₃-based nanocomposites designed by phase-field simulations

Realizing nonvolatile multiple polarization states in ferroelectric-based memories holds great promise for high-density data storage and advanced nanoelectronics. In this study, through phase-field simulations, we proposed a novel nonvolatile multistate memory design using BiFeO₃ (BFO)-dielectric nanocomposites to enhance storage density. By embedding BFO pillars within a dielectric matrix, we stabilized four distinct polarization states. The effects of pillar sizes and electric fields on the stability and switching behavior of these states were systematically investigated, showing that all four states can be effectively switched using either uniform electric fields or localized voltages via a piezoresponse force microscope tip. Simulations of a 4×4 memory cell array further highlighted the potential of this design, achieving a storage density far exceeding that of conventional FeRAM devices. Our work shows the potential of ferroelectric-dielectric nanocomposites on high-density, rapid-switching nonvolatile memory technologies.